Precision quantitative applications using

Hydrodynamic loading is consistently reported to be the more precise injection method. Hettiarachchi and Cheung have concluded that hydrodynamic loading should always be used for high-precision quantitative applications because it is less dependent on the ionic concentration of the sample buffer (62), but running buffer is the recommended sample diluent. 

Another example is LIBS application for real-time identification of carious teeth (Samek et al. 2003). In the dental practice, usually more healthy tissue is removed than ultimately necessary. Carious and healthy tooth material can be identified through the decrease of matrix elements Ca and P in hydroxyapatite and/or the increase of non-matrix elements, typically Li, Sr, Ba, Na, Mg, Zn and C, using pattern recognition algorithms. A fiber-based LIBS assembly was successfully used for this task. As for the case of phosphate ores evaluation, the efforts aimed at normalizing the spectrum collection conditions and procedures, so that the spectra are sufficiently reproducible for precise quantitative... 

Because the spectra obtained from compounds in solution do not contain fine structure, it is not necessary to use spectrophotometers with high resolution. However, it is important to be able to precisely measure the absorbances over a range of several units. The simplest instruments, called spectrocolorimeters, are used for routine quantitative applications. Higher performance instruments designed for the best possible resolution are used in other areas besides analysis. 

Gravimetric methods are based on the quantitative measurement of an analyte by weighing a pure and insoluble compound from the analyte. Analytical balances, which provide accurate and precise data, are used for this purpose. Detailed information on gravimetric methods and their applications can be found in the literature.3... 

Today, CIE is a technique that has been considerably expanded and improved and many applications and modifications have been described see [6] for a review). A CIE pattern looks complicated to the beginner, but regular users rapidly become used to recognizing individual antigens. This technique is not complex to use and interpret. A very important application of CIE is its precise quantitation of a large number of antigens simultaneously. 

The dynamic range of a mass spectrometer is defined as the range over which a linear response is observed for an analyte as a function of analyte concentration. It is a critical instrument performance parameter, particularly for quantitative applications, because it defines the concentration range over which analytes can be determined without sample dilution or preconcentration, which effects the accuracy and precision of an analytical method. Dynamic range is limited by physiochemical processes, such as sample preparation and ionization, and instrumental design, such as the type of mass analyzer used and the ion detection scheme. 

The most accurate and precise quantitative measurements do not employ the current measurement methods described thus far, but instead use ion counting techniques. The use of ion counting techniques in mass spectrometric analyses of very small samples was first intoduced (Barton 1960 Ihle 1971) for determination of relative isotope abundances in radioactive metals, but the first published report of application to trace level quantitation of organic analytes by GC/MS appears to have been somewhat later (Picart 1980) modem practice uses the same fundamental principles but with greatly improved detector and electronics technology. 

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